| abstract |
The use of an oxide semiconductor film having stable electrical properties provides a semiconductor device with stable electrical properties and high reliability. Further, by using an oxide semiconductor film having high crystallinity, a semiconductor device having improved mobility is provided. By forming an oxide semiconductor film having crystallinity in contact with the insulating film having a reduced surface roughness, an oxide semiconductor film having stable electrical characteristics can be formed. Thereby, it is possible to provide a highly reliable semiconductor device by imparting stable electrical characteristics to the semiconductor device. In addition, it is possible to provide a semiconductor device with improved mobility. |